The door opens at the first candle and there is a room behind it: round, small, one iron bed, walls covered in handwriting edge to edge.

CorvinaRules. Anything said in there is true, including what you say to keep from saying the other thing. Anything done is written.

MioneAnd the margin?

CorvinaThe margin is Porter's. Everything you do not say out loud, he has to write down instead.